Change countries after paying visa fee in India

Hi - I am currently on H1b and I qualify for dropbox. I filled the ds160 and paid the visa fee and waiting for a dropbox slot to open in India. But as I understand there is a severe shortage of dropbox appointments and I am having a tough time getting one. I see that people are successfully going to Canada to get their H1B’s stamped. What is the process for me to book an appointment in Canada? Am I allowed to do that while having an active DS160 submitted to the US travel docs? Should I simply ignore the existing application and file for a new ds160 and create a new visa application?